Time of Operation Not Linked to Postoperative Mortality

The timing of general surgery and the moon phase are not associated with 30-day mortality after surgery, according to a study published in the December issue of Anesthesia & Analgesia.

FRIDAY, Dec. 2 (HealthDay News) -- The timing of general surgery and the moon phase are not associated with 30-day mortality after surgery, according to a study published in the December issue of Anesthesia & Analgesia.

Daniel I. Sessler, M.D., from the Cleveland Clinic, and colleagues investigated whether the timing of general surgery (time of day, day of the week, July/August versus other months) and moon phase were independently related to 30-day mortality, or to a composite of in-hospital complications. A total of 32,001 patients who underwent elective general surgery between January 2005 to September 2010 were analyzed for binary outcomes according to the hour of the day (6 a.m. to 7 p.m.), day of the workweek, month of the year, and moon phase in which the surgery was started. Multivariate logistic regression was used to evaluate 30-day mortality as a binary end point, after adjusting for the risk stratification index.

The investigators found that a four hour relative increase in the time of day was associated with an adjusted odds ratio (aOR) of 1.23 (P = 0.09) for 30-day mortality. Similarly, the day of week was not associated with 30-day mortality (aOR, 0.99 for a relative increase of one day; P = 0.85). Compared to other months, mortality was no more frequent in the months of July and August (aOR, 0.72; P = 0.22). There was no significant association between the moon phase and mortality (P = 0.72). Time-dependent differences in composite complications were nonsignificant.

"Elective general surgery appears to be comparably safe at any time of the workday, any day of the workweek, and in any month of the year," the authors write.